Key blank



March 10, 1 931. R, SIMON 1,795,318 I KEY BLANK Filed Jan 8. 1930 (inventor: 66156) Sinwzv 8 3M? attozmmg tl- Patented ar. re, 1931 1,795

UNITED STATES PATENT OFFICE REUBEN snvron, or LEOMINSTER, MASSACHUSETTS 1 KEY BLANK Application filed January 8, 1930. Serial No. 4191277.

Keys for locks, in the nature of their use, sible for all sales representatives of all are necessarily highly diversified. Not only makes of automobiles to carry in stock a do the keys of different manufacturers vary relatively small number of inexpensive key widely in their patterns but an equally wide blanks corresponding to the keys in use on 5 variance of the keys of each manufacturer the locks of the make of automobile which must be provided. To enable the user to obthey handle and to duplicate keys from such tain a duplicate conveniently has always preblanks upon demandof their customers by a sented a problem which can hardly be said to few minutes unskilled effort on the part of have been solved satisfactorily up to the presan ordinary shop mechanic using a standard 10 ent time. One method employed is to use the tool. A further object of the invention is to key which is to be duplicated as a pattern for provide -a key blank which may be readily filing down a proper blank by hand. This marked during the course of its manufacture method, of course, requires possession of the with such indicia as may be necessary to enkey which is to be duplicated and some little able the improved method to be practiced in 15 skill on the part of the locksmith. Another cutting a key therefrom. A further object method is for each manufacturer to number of the invention is to provide such indicia on its keys and place in the hands of those hava key blank as will enable any one of a ing suitable equipment a code which reveals vari ty of keys to he cut from the blank the the blank and pattern of the key with referindicia itself being of such a character as to 20 ence to its particular number. With such in i ea ly t0 h or m n a g data and a machine a duplicate key an b reference tothecode) what operations are to made. The duplicating machine employed be performed to give the desired completed for preparing a key having a particular patpattern. tern as revealed by the code book is expensive While it will be understood by one skilled 25 and its general. use thereby restricted. The in the art that key blanks differ in cross secresult is that today it cannot be said that the tional form and that keys differ in pattern user of a key has at his command a wideaccording to the number of tumblers conspread and convenient service for obtaining trolled by the particular key and that the relaa duplicate. With the recent widely intive dimensional spacing and depths 0f 30 creased use of locks on automobiles, for innotches or slots in the patterns of keys may stance, this inconvenience is a condition that vary, all such differences are recognized and has come home to the public. With increascoded in accordance with the present day ing demands for service by the public the practice. This bein true it will be undermanufacturers' of automobiles have become stood as the descriptlon proceeds herein that 35 sensitive to the practical difficulties of meetthe invention is applicable to any key blank ing this demand for service in the duplication although being illustrated in connection with of keys for the locks on the cars which they blanks in which the cross sectional formand sell. dimensional relationships of the pattern are The principal object of the present invenassumed by way of illustration.

40 tion is to provide a method which shall be The improved'keyblank in accordance with 0 simple and inexpensive for the making of the invention will be provlded with a series keys in accordance with a known pattern. of lines which will indicate the depths of the By this method it is sought to make it posvarious notches or slots used by the particular sible for keys to be quickly duplicated withmanufacturer in that type of key. It will be 5 out the use of special equipment or tools, by provided with indicia indicating the dlmenunskilled workers. By such a provision it Sional spacing of the notches and slots of that becomes possible to establish 'a wide-spread particular type of key and in the number to service through all ordinary agencies for the which such key is formed with notches and duplication of keys. For instance, pursuant slots depending on the number of tumblers to the improved provision it becomes poswhich the key is adapted for control of.

The invention will be described in greater detail with reference to the key blanks illus- Figure 3 is a view in cross section on an enlarged scale taken on the plane indicated by the line 33 of Figure 1 and looking in the direction of the arrows, the indicia being exaggerated as consisting in grooves milled or etched in the blank.

Figure 4 is a view in side elevation of a key blank of a somewhat difierent type having ungrooved sides and in which rectangular slots are cut in the edge to constitute the pattern.

The key blank a shown in Figures 1, 2 and 3 may be grooved or ribbed along one or both of its side faces as indicated in Figure 3, the invention not being concerned with the cross sectional form of the blank but being applicable to blanks of varying forms. A key formed from such a blank usually has along its top edge a a series of notches. Such notches are of a predetermined number depending on the number of tumblers in the lock for which the key is made. Further, these notches have their apices spaced apart a predetermined distance and each notch measured from the edge a is of a predetermined depth. In the code book now furnished to locksmiths there will be set forth, for example, under a particular key number which every key bears, the corresponding blank which is to be used for duplicating such key. Such a blank, of course, has a cross sectional form corresponding to the key whose number is being considered. The code book will, in addition, state the number of notches along the upper edge, the distance of their apices apart, and the depth of each notch. Under the present day practice this data is used for setting a special key cutting machine so that it will cut the desired number of notches in the specified dimensional relationship and to the specified depths. Such a machine is expensive and its use comparatively limited for that reason. In accordance with the present invention the key blank a when manufactured has formed on one face a series of parallel lines a a a which may be milled, etched or otherwise formed as may be found most desirable. The line a is spaced a predetermined distance from the upper edge (1 depending on the standardized depth of such notches as the particular manufacturer may employ in the particular key under consideration. The next line a is similarly spaced from the upper edge a a predetermined distance de pending on the next greater depth of notch that may be required in the particular key. Similarly, the third line a is spaced from the upper edge a such a distance as will indicate the depth to which the third deepest notch may be required. While it is frequently true that the depths of the various notches are multiples of the shallowest notch this is not always true and is not a condition which is important in the present invention because as indicated above the determining factor in each instance is the depth to which each notch is to be cut considering the top edge a as the base line. Having this in mind it will be evident that the three lines a a and a and any additional number of lines, where required, shall represent the notch depths. The blank a is also provided in accordance with the invention with suitableindicia to indicate the distance between the apices of the various notches which are to be out. It is immaterial what form such indicia shall take and where it shall appear on the surface of'the key blank. In Figures 1 and 2 transverse lines a a, a, a a", a are shown as provided on the top edge a and these lines are also shown as extended down the side face of the blank to intersect the longitudinally extending parallel lines a a a It may be found equally convenient to omit the lines a a, etc. fro-m the top edge or from the side face and to place them on the reverse face and the invention is not to be limited as to such details. The purpose of these lines is to indicate for the particular key blank the distance between the apices of the several notches to be cut in its top edge.

With the blank formed in the manner described and preferably during its stage of manufacture it is ready for use, to be made when required, as a duplicate for any one of a great variety of keys having different patterns. When the number of the key to be the notches. These depths are given in the code book in their order from one end of the i key to the other.

The method employed in making the desired key having the improved blank in stock is as follows: A convenient tool, preferably a file, is employed to cut in the notches in succession along the top edge a. The workman has determined from the code book that the first notch viewed at the end of the key blank asshown in Figure 1 is to be two units in depth. He starts to file on the indicating line a knowing that on that line is to be the apex of the notch. He files until he has reached the, second line a as viewed from the side of the key blank and when he reaches units in depth conforming to the code book and its apex is properly placed. He will determine from the code book that the second notch which is to have its apex on the line a is to be filed one unit in depth terminating at the first indicating line a From the code book he will find that the third and fourth notches are each to be two units in depth and he files them in on their space lines a a respectively, until their apices fall on the depth line a The code book will tell him for the particular key that the fifth notch, which is to be cut at the line a is one unit in depth and he will stop filing when this notch has reached the first line (2 The sixth notch cut on the line a is shown to have a depth of three units and so will extend down to the guide line a. When his filing is thus completed, using the indicia as described, an accurate and correct duplicate of the particular key by number will be completed.

Figure 4 shows a somewhat different type of key blank and is included merely to em phasize that the invention is not limited in its use to any particular type since the principle may be incorporated in any blank. In this figure the blank I) has no grooves-:or ribs on its side faces and is intended for use in a lock where rectangular slots along the bottom edge I) are required in accordance with a predetermined pattern. This blank will be manufactured with a plurality of parallel guide lines 6 b, b on one face spaced predetermined distances from the edge 1). Similarly, a series of guide lines 6 b b b 1), b b Z2 may be provided on the sid face intersecting the first named guide lines or, as pointed out hereinbefore, these last named lines may appear only along the edge of the blank or on the opposite face. From the code book, to make a particular key, having the proper blank 6, slots ofstandard form will be filed in at intervals as indicated by the code book each slot being of a depth directed by the code book. It will be noted that the edge of the blank is not indented opposite the guide lines 6 b, but this is a condition that will be indicated by the code book since the edge I) can be regarded relatively as the base line and the bottom of a slot of least depth, all of the other slots being related thereto in depth as indicated by the other guide lines 6 ,6 6 p The, improved key blank and method of making keys therefrom lend themselves to the widest use. Having the blanks in stock I it becomes possible for anyonewith code directions as to the depths of the successive notches to make a key without any skill merely following the indicia as directed. The resulting pattern of the key is necessarily that desired. No special equipment is needed, no skill is required, the capital investment is only that of such key blanks for keys as may need to be duplicated and the While the method of cutting the notches as described refers to their cutting in succession beginning from the end of the key blank, one skilled in the art will understand that it may be better practice to cut all of the shallowest notches first and proceed then to the cutting of the next deeper notches and so on.

Another point to understand in connection with the invention is that it is not limited to the application of the indicia to the key blank during its manufacture since such indicia can be applied by hand at any time through the use of any suitable tool or device.

The further point that will be understood by one skilled in the art is that the top edge a of the key blank as described is not necessarily the number 1 cut or base line according to the code but this fact makes no difference in the understanding of the invention since if it is not the base line all of the other notches required by the code for a particular key will have the depth indicated in the code.

It will be evident that the blanks may be provided with indicia which show only the spacing of the notches or only the depth of the notches or both since the provision of indicia for either spacing or depth would have considerable practical value commercially in the making of keys from blanks.

It is intended by the appended claims to cover the principle underlying this invention in its broadest application and itis to be undeistood that where this principle is embodied by the means set forth herein enabling keys to be made in accordance with the im proved method no limitations areto be imposed-as to the character of the key blanks nor on the means employed for generating indicia.

What I claim is:

,1. A key blank provided with indicia in predetermined dimensional relationship as to depth to befollowed in cutting according to co e.

2. A key blank provided on its face with parallel lines spaced apart at predetermined intervals as to depth to be followed in cutting according to code.

3. A key blank provided with indicia in predetermined dimensional relationship as to location and depth to be followed in cutting according to code.

4. A key blank provided on its face with parallel lines spaced apart at predetermined intervals as.to depth to be followed in cutting according to code and other lines at prede termined spaced intervals to be followed as to location in said cutting.

5. A key blank provided on its face with parallel lines spaced apart at predetermined intervalsfrom one edge of the blank to be followed as to depth in cutting according to code and transverse lines along the said edge of the blank at predetermined spaced intervals to be followed as to location in said cutting.

This specification signed this 2d day of January A. D. 1930.

REUBEN SIMON. 

